Generally, it is desirable to recycle and reprocess used petroleum based products, such as waste lubricating oils, or oil derived from carbonaceous waste. Reprocessing or re-refining can recover a substantial amount of product from spent lubricants and other carbonaceous waste materials in an environmentally safe manner.
High severity hydroprocessing may be used to produce highly saturated, hetero-atom free oils that can be used as either finished or intermediate products, such as for example, lube oil blending stocks, petrochemical feedstocks, and specialty oils in liquid transportation fuels. Technology that is used for re-refining used or waste lubricating oils often needs improvements to adapt to changing feedstocks to include nontraditional sources of hydrocarbons.
Sometimes it is desirable to upgrade or enhance the hydrotreated or hydroprocessed used lube oil (e.g. re-refined lube oil). Particularly, oils can be segregated and defined by different grades, and higher grade products can have higher saturated content (e.g. low aromatic content) with preferably lower naphthene and higher linear and branched paraffin contents, which improves certain properties of the products. As a result, higher grade products, which are commercially desirable, can be made. Unfortunately, facilities that are designed to manufacture re-refined lube oil products at certain grades often do not provide higher quality products with low aromatic content and relatively low naphthene and high linear and branched paraffin contents.
Accordingly, it is desirable to provide processes that enhance a re-refined lube oil stream to provide an improved quality product that has a low aromatic content and relatively low naphthene and high linear and branched paraffin contents. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention in the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.